[Harrison_M240]

Hi all,

My first post on this forum so apologies if any mistakes are made or I post in the wrong area

I own a 2018 M240i 8AT and since I've had the car I've been hearing this "whine"... at first I thought it was coming from the gearbox and read into it so much I was convinced the box was faulty, given that alot of people seem to be experiencing whining from the 8AT. However, I'm 99% sure its coming from the engine now and sounds as if its the pulleys whining, after watching a few YouTube videos of the B58 it seems as though I can hear it in all of them so I'm assuming it's just a normal mechanical noise I'm hearing from pulleys and belts as it also seems to be rev related too (higher revs - higher pitch) almost like a winding up noise and once letting off the accelerator you can hear it "wind down" if that makes sense? also makes the noise whether in neutral, park or drive.

If you haven't already worked it out I'm pretty paranoid about noises on the car especially mechanical related ones but thought I'd just check in to see if what I'm hearing is totally normal or not? And if anyone else has noticed the whiney engine whilst increasing the revs. I appreciate without a video its hard to tell so I will try to post one up later.

Thanks in advance all.

Harrison.

[BrettKA7]

Haven't noticed this in my M240i.

My ZF8 definitely whines after a canyon run, but that's normal. Oddly, I sometimes get a whine immediately after a u-turn… hopefully that's normal as well. Unable to duplicate it on purpose though.

[BigBødy]

Yup, almost sounds like a supercharger. Only really hear it with the windows down, pedal on the floor and from low rpm. Normal.

[Stefo]

Have the same whine with my 2017 M240xi. Really notice it at highway speeds 50-70mph with windows closed and accelerating or coasting. Have gotten used to it.

[vandridine]

I always have the supercharger whine after driving hard in the mountains, local BWM shop said it is normal

[TakoMako]

Both my m240i and 340i GT does it, but m240i is louder. Potentially less sound deadening.

[mevans313]

I have it in my 2018 M240 xdrive 8AT. I can only hear it when flooring it from a stop. As far as I can tell it’s normal. It did scare me for a while though lol

[Wozich]

I have this supercharger noise on my M240i as well. I have the car for 4 years and I think it has become louder and more frequent. Got me a bit worried. My car has 70.000km.
Before I thought I could only hear it when I drove the car hard and the engine was hot (no track driving though). But now every time I rev it beyond 3500 rpm I can hear it.
Apart from the noise everything is normal. Should I have the car checked anyway or leave it?

[SpencerC_6MT]

'17 M240i 6-speed. Haven't noticed anything like this, but it could be an anomaly specific to ZF8 motors without actually relating to the transmission itself.

[Pezza2610]

My 2017 M240i makes the same whine the OP mentions when stationary and out of gear. I put it down to the engine just doing its thing, it is in the bay backwards so all the chains etc are at the bulkhead so I imagine they'll just be naturally louder. It does also have the whiney gearbox I.e it makes the noise in reverse and I think it does it in the lower gears, but you could spend literally days online finding people saying theirs does it too and those cars still going strong so I've just learnt to live with it.

I'm just of the mindset now that the car is smart enough to tell me if something is going wrong with it so no point trying to convince yourself that you think there is something wrong. Unless you have the knocking steering rack, in which case the car won't tell you jack all but it is cheap to fix at least.

[Mjolnir12]

Do you have ASD on or off? With ASD off on mine there is definitely some whining component of the sound at higher RPMs, but it isn't dominating the sound and doesn't sound like anything out of the ordinary.

[Zircular]

Mine whines a bit but I don’t think there’s a reason to be concerned. I chalk it up to the timing chain running right in front of the firewall. My Volvo has kind of a wonky setup too…timing chain at the rear of the engine with a power take off driving the serp belt and all of the accessories right next to it over the transaxle. Not the same because transverse, but with all that equipment right in front of the driver you hear things. NBD to me.

[Zircular]

Here's my best attempt at a *****y video of what mine sounds like from the cabin. The whine that changes pitch with engine speed is pretty easy to hear, though you'll probably want ear buds.

Car is fully warmed-up but temperature doesn't seem to matter...this is just what it sounds like.

**edit**
Just came across an old thread that talks about it (mostly on the second page). One post toward the end of the thread indicates that the whine might actually be a wastegate thing rather than the timing equipment. I can’t decide if that makes sense or not.

https://f30.bimmerpost.com/forums/sh....php?t=1204279

[Zircular]

So after all my nonsense about the whine being no big deal, I’ve talked myself into believing that my specific noise may be an actual problem. Possibly a bad input shaft bearing in the trans. Figures.

First, mine seems unusually loud compared to every video I can find. The whine really comes through above other noises at any legal speed. I coded off ASD the other day just to see and it’s very much a real sound. The video I posted above is decently representative.

I don’t think it’s related to the accessories or timing chain because it doesn’t do it unless the car is in gear. (Although the pitch does follow engine RPM perfectly.) To test this I got up to a speed where the whine is most pronounced, shifted to neutral, and brought the engine back up to the same speed. The whine almost disappears in that scenario. (I have to go back and compare neutral to clutched in.)

I don’t think it’s the wastegate thing either because it whines while engine braking as well as accelerating, and while crawling around at parking lot speeds. Nothing exhaust related should make that much noise at low engine loads.

Finally, it sounds to me like gear whine. And I have noticed difficult 3rd and 4th gear engagement on occasion. If a bad bearing has thrown a shaft out of alignment it may actually be gear noise that I’m hearing.

Opinions? Have I just fallen victim to forum hypochondria?

[gippy]

i'm experiencing everything that you're all describing above. 2016 440i, currently 42k miles.

after years of sitting on it (and then covid etc.), dropped it off at the dealer yesterday.
I took the technician out for a test drive, replicated the sound, which he acknowledged.

They've had the car today and couldn't find anything wrong with tensioner/pulley/belts (or something) etc. (that was his initial theory), called me today and said that BMW Germany have asked to place some mics around the engine, turbo and gearbox, they're going to record the noise and send it across to them to find out if its normal or not.
I'm not convinced the mics will pick it up if they're being placed directly next to components, maybe they'll also record from interior, not sure.

what i find strange is how it appears then dissappears, the moment you stop driving hard.
Once car is warmed up etc... i have to do maybe 2-3 WOT pulls from 10mph to 50, the noise will appear on maybe the 3rd run, and remain, as i repeat the pulls.
Then the moment i stop, cruise around for a bit, and try it again - i have to again do 2-3 pulls for the noise to reappear.
If it's transmission related, wouldn't the noise be present all the time?

i have a feeling BMW will just say 'yup its normal' and be done with it, who knows. The problem is the technician has to drive it for it to be actioned with BMW, so all of this is now dependent on him being able to do the above tests in a competent manner... he was sat next to me as i did it so hopefully he won't pussy the car around.

I'm not fussed either way, at least i've done my bit and flagged it - there isn't any moment during daily use where i actually do continuous pulls, so it's never an issue.
Guess i'll continue extending my comprehensive warranty indefinitely....

[Zircular]

That’s the 8 speed auto?

[gippy]

Originally Posted by Zircular

That’s the 8 speed auto?

yup.

[Zircular]

I figured as much from the sound. Nice that BMW is going to work with you on troubleshooting, although I think you'll be proven right on the outcome. Very few "my car whines" complaints on these forums seem to be resolved with a repair. (I've probably been through every thread at this point...quite the rabbit hole.) Yours is very likely the "ZF whine." It's pretty distinctive, seems to be a common annoyance, and doesn't seem to have any mechanical significance. People have had those boxes replaced under warranty only for the new one to do the exact same thing. I don't think I've come across a satisfactory explanation for the sound. Plus side, they never seem to blow up?

Here's my master list of explanations for generic whine complaints:

• Belt-driven accessories (duh)
• Timing chain problems (N20/26 mainly, others as the plastic guides age and fail)
• Intake/turbo/waste gate sounds
• Exhaust leaks
• Differential gear noises (especially ///M cars)
• “Normal” ZF 8HP transmission sounds (mainly when hot)
• Other abnormal transmission sounds
• X-drive transfer case issues
• ASD acting up
• Your significant other (typically from passenger side)
• and “Don’t worry, they just do that”

I think these are often conflated on the forums since different sources can often be described similarly. We need a fault tree or something.

I'm still fairly convinced that my whine is coming from the input side of the gearbox, although I'm back off the ledge. I'll troubleshoot it as far as I can and then let it go. I replaced the fluid yesterday and pulled a sample for used oil analysis. If there's really a problem it should show up on the report.

I did come across one interesting wrinkle, though. The RealOEM parts catalog for manual M240s lists a "Noise insulation, Transmission Housing" part # 23108609376. What's weird is that it doesn't apply to a very small gap in production. It's listed as discontinued from 12/2016 and then comes back for the MY18 LCI (mid-2017 and on). I have a very late (5/2017) pre-LCI build, and I confirmed while I was under there yesterday that the gearbox is indeed naked. It makes me wonder if I'm hearing 100% normal manual transmission gear whine that others don't report because most cars are insulated against it. Just a theory but it seems plausible. If valid, I can claim that it's a "feature."

[dradernh]

Originally Posted by Zircular

I did come across one interesting wrinkle, though. The RealOEM parts catalog for manual M240s lists a "Noise insulation, Transmission Housing" part # 23108609376. What's weird is that it doesn't apply to a very small gap in production. It's listed as discontinued from 12/2016 and then comes back for the MY18 LCI (mid-2017 and on). I have a very late (5/2017) pre-LCI build, and I confirmed while I was under there yesterday that the gearbox is indeed naked. It makes me wonder if I'm hearing 100% normal manual transmission gear whine that others don't report because most cars are insulated against it. Just a theory but it seems plausible. If valid, I can claim that it's a "feature."

Another data point: I have a 5/2017 build with MT and haven't heard my car make any untoward sounds. I don't know if the housing is present, though.

Below is what I see on realoem's cross-reference for part no. 23108609376, while the parts explosion shows the housing is effective only through 12/2016. It might be worth a call to a dealer's parts department to find out if the part should indeed be on your car. Or maybe I'm misinterpreting how realoem presents its data.

[Zircular]

Good info! Here's what I see when I browse parts for a mid-2016 build (under "Gearbox mounting parts):



When I browse the same for a 5/2017 build that part is grayed-out in the image and absent from the parts list. Weird.

*edit*
Good suggestion about talking to a dealer parts department. I may just do that…see if they can clear it up.

[gippy]

They're changing the turbo.
Looks like i'm going to be stuck in the courtesy car a few more days.
No other details given yet.

[Zircular]

Beats shrugging and sending you on your way. Let us know how it turns out!